Track and field is a sport that combines various athletic contests based on the skills of running, jumping, and throwing. Regular jumping events include long jump, triple jump, high jump and pole vault. Long jump and triple jump are judged on the distance jumped horizontally. High jump and pole vault are judged on the vertical distance cleared.
High jump and pole vault require that jumpers clear a crossbar, sometimes referred to simply as a bar, set at a measured height. The crossbar is set between a pair of standards, sometimes referred to as uprights. The standards have a series of rest pins, sometimes called pegs or mounts at measured heights. The crossbar is balanced on the pins, with one end of the crossbar placed on a pin on a first standard and on a pin at the same height on the second standard.
Competitors take their attempts individually, only one competitor attempting to clear the crossbar at a time. The crossbar is set an initial height and all competitors have a choice to attempt or pass. Once all competitors have had at least three attempts to clear the bar or have passed, the crossbar is raised up a predetermined amount.
Crossbars are set by the workers using a tool called a crossbar placer, crossbar lifter or “putter upper.” Some are telescoping to cover a wide range of heights. Others are simple fork-ended poles. The workers place the crossbar on the pins and the workers and judges use visual checking to determine that the bar has been consistently and properly placed.
Crossbars are moved upwards on the standards after each round. The workers set the bar higher and one or more of the judges confirms that the bar has been properly set and measures the distance from the center of the bar to the ground.
All competitors in the event should be attempting a jump under theoretically the same conditions. However, often one competitor will knock the crossbar off of the pins on the standards, requiring a pair of workers to replace the crossbar on the pins. A judge must affirm that the bar has been properly reset before the next individual makes an attempt.
Crossbars generally are made from fiberglass. Overtime, the crossbar may develop a slight bow that is not necessarily centered between the standards. Further, a crossbar can be repaired by slipping a sleeve over the broken section. In order for the competitors to compete under the same conditions, it is important that any bow in the crossbar or repair be consistently placed relative to the center of the bar and the standards.
Crossbars have a circular cross-section, making them capable of rotating or rolling when sitting on the pins. The crossbar has a pair of rubber crossbar ends covering each end portion of the bar. The rubber crossbar end sits on the pin, preventing the crossbar from rotating on the pin.
Some rubber crossbar ends have at least one flat side and a rounded top, and some have four flat sides forming a square surrounding the circular cross-section of crossbar. Others have a semicircular portion extending from a round portion, the flat diameter of the semicircular portion presenting a flat surface to the pin. Regardless of the overall shape, all rubber crossbar ends present a flat surface to present to the pins, preventing the crossbar from rotating.
While these units may be suitable for the particular purpose employed, or for general use, they would not be as suitable for the purposes of the present disclosure as disclosed hereafter.
In the present disclosure, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date, publicly available, known to the public, part of common general knowledge or otherwise constitutes prior art under the applicable statutory provisions; or is known to be relevant to an attempt to solve any problem with which the present disclosure is concerned.
While certain aspects of conventional technologies have been discussed to facilitate the present disclosure, no technical aspects are disclaimed and it is contemplated that the claims may encompass one or more of the conventional technical aspects discussed herein.